1. Field of the Invention
The present invention relates to a fixing mechanism and a related optical engine, and more particularly, to a fixing mechanism for fixing a light valve and a thermal module of an optical engine and the related optical engine.
2. Description of the Prior Art
Please refer to FIG. 1. FIG. 1 is a schematic view of a projector in the prior art. The projector 10 includes an optical engine 12 including a covering 14, a light source 16, a converging lens 20, a color wheel 22, an integration rod 24, a condenser lens 26, a stop 28, a relay lens 30, a total reflection prism system 32, a light valve 34, and a projection lens 36. The covering 14 is for covering internal components of the optical engine 12. The light source 16 includes a parabolic reflector 161. Light beams 18, generated by the light source 16 are reflected by the parabolic reflector 161 and pass through the converging lens 20 and then converge into the color wheel 22 that is formed by a series of red, green and blue filters. After the light beams 18 pass through the color wheel 22 to be transformed into colored light beams 181, the colored light beams 181 enter the integration rod 24 to uniform the brightness of the colored light beams 181, and then sequentially pass through the condenser lens 26, the stop 28, and the relay lens 30, and finally converge into the prism illumination system 32 which is capable of reflecting the colored light beams 181 with a reflection surface 321 onto the light valve 34. The light valve 34 is formed with a plurality of pixel lens which are disposed in a matrix and capable of pivotably rotating within a range of +12 to −12 degrees. The light valve 34 can be a digital micro-mirror device (DMD). When the light valve 34 is in an ON state, the pixel lenses reflect an incident light beam onto the projection lens 36. When the light valve 34 is in an OFF state, the pixel lenses reflect an incident light beam onto a region outside of the projection lens 36. The light valve 34 selectively reflects the colored light beams 181 through the prism illumination system 32 and further through the projection lens 36 and finally projecting onto the screen 38. The projector 10 further includes a housing 40 and a control unit 42. The housing 40 is for covering the optical engine 12 and the control unit 42. The control unit 42 is electrically connected to the light valve 34 for switching the light valve 34 in the ON or OFF state.
The size of the projector 10 and the optical engine 12 thereof are getting smaller trendily causing increase of the thermal density in the condition of the same light power so that the temperature of the light valve 34 inside the optical engine 12 increases accordingly. When the inner temperature of the projector 10 increases, the operating stability reduces, especially for the precise light valve 34. For solving the above-mentioned problem, a thermal module is installed on the light valve 34 for dissipating heat generated by the light valve 34. Please refer to FIG. 2 and FIG. 3. FIG. 2 is a diagram illustrating the combination of the light valve and a thermal module in the prior art. FIG. 3 is an exploded drawing illustrating the combination of the light valve and the thermal module in the prior art. The optical engine 12 further includes the thermal module 44, a fixing mechanism 46, and an interface board 52. The thermal module 44 is disposed on a side of the light valve 34 and connected to the light valve 34 for dissipating heat generated by the light valve 34. The light valve 34 and the thermal module 44 are fixed on the covering 14 of the optical engine 12 with different fixing components and different elastic components respectively. The fixing mechanism 46 includes a plurality of fixing components 48a, 48b, 48c, 48d which can be screws, and a plurality of elastic components 50a, 50b, 50c, 50d which can be springs and sleeve on the fixing components 48a, 48b, 48c, 48d respectively. The fixing components 48a, 48b, 48c, 48d pass through the interface board 52 and are screwed to the covering 14 of the optical engine 12. One end of each elastic components 50a, 50b, 50c, 50d is connected to one of the fixing components 48a, 48b, 48c, 48d. The other end of each elastic components 50a, 50b, 50c, 50d is connected to the interface board 52. The fixing mechanism 46 further includes a fixing means 54 which can be a screw, and an elastic means 56 which can be a wire spring or a clip. The light valve 34 is fixed on the covering 14 of the optical engine 12 by the fixing components 48a, 48b, 48c, 48d and the elastic components 50a, 50b, 50c, 50d. The thermal module 44 is fixed on the interface board 52 by the fixing means 54 and the elastic means 56.
For reducing numbers of the fixing components for the light valve and the fixing means for the thermal module, the fixing component and the fixing means can be integrated as one piece. Please refer to FIG. 4. FIG. 4 is a diagram illustrating the combination of the light valve 34 and the thermal module 44 according to another embodiment in the prior art. The fixing mechanism 58 includes a plurality of fixing means 60 and a plurality of elastic means 62 which are sleeved on the fixing means 60 respectively. The fixing means 60 can be screws, and the elastic means can be springs. The fixing mechanism 58 further includes an interface board 64. The fixing means 60 pass through the interface board 64 and screwed to the covering 14 of the optical engine 12. One end of the elastic means 62 is connected to the fixing means 60, and the other end of the fixing means 62 is connected to the thermal module 44. Besides, the fixing mechanism 58 further includes an elastic component 66 which can be a leaf spring or a clip. Two ends of the elastic component 66 are connected to holding surfaces of the fixing means 60 respectively, and a central part of the elastic component 66 presses against the interface board 64 so as to fix the light valve 34. The light valve 34 is fixed on the covering 14 of the optical engine 12 by the fixing means 60 and the elastic component 66. The thermal module 44 is fixed on the covering 14 of the optical engine 12 by the fixing means 60 and the elastic means 62. It means that the light valve 34 and the thermal module 44 are fixed on the covering 14 of the optical engine 12 by the same fixing means 60 but different elastic components (the elastic component 66 and the elastic means 62). Because holding positions of the elastic component 66 and the elastic means 62 are different, there is a need to apply special screws or other components to provide different holding surfaces. As shown in FIG. 4, corresponding holding surfaces of the fixing means 60 need to be lathed for providing the two ends of the elastic component 66 to lean against.
In conclusion, there are more and complicated fixing components of the fixing mechanism for fixing the light valve and the thermal module so as to provide different holding surfaces for the elastic components of the light valve and the thermal module, and the assembly procedure is more complicated. There is a need to find an efficient fixing mechanism with low cost for fixing the light valve and the thermal module.